ISO 24679-1:2019

Overview

ISO 24679-1:2019 - Fire safety engineering - Performance of structures in fire - Part 1: General defines a performance-based methodology for assessing how structures behave under real fire conditions. Aligned with ISO 23932-1, it guides engineers through a quantified engineering approach to evaluate structural fire performance over the entire fire time history (including cooling), and to judge consequences against fire safety objectives such as life safety, property protection, and environmental protection.

Key Topics

• Performance-based assessment: Methodology for evaluating structures in realistic fire scenarios rather than relying solely on prescriptive fire-resistance tests.
• Design strategy and process: Steps for a practical design process, trial design plans, and documentation requirements.
• Scope definition: Identifying built-environment characteristics, fuel loads, mechanical actions and project scope for structural fire analysis.
• Design fires and scenarios: Selection of design fire scenarios and thermal actions that reflect real enclosure conditions, ventilation, and fuel arrangements.
• Thermal response: Quantification of temperature or heat-flux variations in enclosures and how they affect structural elements.
• Mechanical response: Assessment of load redistribution, restraint effects, interaction between elements, and structural failure modes under fire.
• Performance criteria and objectives: Defining objectives, functional requirements and measurable criteria to judge compliance with fire safety goals.
• Methods guidance: Use of calculation methods, experimental methods, test data and engineering judgement in structural fire evaluation.
• Factors to consider: Material properties, continuity/restraint effects, test result applicability, and fire spread routes.

Applications

ISO 24679-1 is intended for fire safety practitioners and structural/fire engineers who use performance-based design methods. Typical uses include:

• Assessing new or existing buildings, bridges, roof structures, grandstands or other built environments exposed to realistic fire scenarios.
• Developing trial designs and verifying whether structural systems meet life-safety and property-protection objectives.
• Integrating thermal and mechanical analyses to support alternative compliance routes where prescriptive codes are insufficient or overly restrictive.
• Informing specification of active or passive fire protection measures, retrofit strategies, and cost-effective design options.

Practical benefits include improved reliability of fire safety decisions, clearer documentation for approvals, and potential cost savings through optimized fire protection strategies.

Related Standards

• ISO 23932-1 - General principles for fire safety engineering
• ISO 834-1 - Fire-resistance tests - Elements of building construction
• ISO 13943 - Fire safety vocabulary
• ISO/TR 16576 - Examples of fire safety objectives and criteria
• ISO/TS 16733-2 - Selection of design fire scenarios and design fires

Keywords: ISO 24679-1:2019, fire safety engineering, performance-based design, structural fire performance, design fire scenarios, thermal response, mechanical response.